A research team from India's IIT (Institute of Technology) Madras has officially developed the world's first iron-ion battery, which promises a low-cost stable alternative to the existing mainstream lithium-ion battery.

The battery consists of an anode made of low-carbon steel, instead of pure iron, plus a cathode made of vanadium pentoxide, which is suitable for the movement of iron ion, due to its larger gap. The iron-ion battery also uses iron chlorate as electrolyte.

Compared to the traditional lithium ion batteries, the newly developed batteries from IIT are much more cost effective, and features slightly better storage capacity and stability. The iron-ion batteries are also much more safe to use, due to the inability of iron to produce dendrites, which prevents a short circuit from happening when the electricity is discharged, according to the research team’s findings.

According to the research team, the other notable benefit of iron is its favorable physical and chemical properties. “The redox potential of iron ion is higher than lithium-ion, and the radius of the Fe2+ ion is nearly the same as that of the lithium-ion,” the team claims. “These two favorable properties of iron have been overlooked for so many years. And that’s the reason why we don’t have iron ion rechargeable batteries,” the team added.

Despite having some noticeable advantages over lithium ion batteries, the newly developed iron ion batteries will still need to undergo further optimization and testing, as the research team’s findings have showed that it is only capable of 150 cycles of charging and discharging for the time being. At the present stage, the energy density of the battery is also only able to reach around 220 Wh/kilo, which is only around 55-60% of the 350 Wh/kilo of energy density for lithium-ion battery.